I have just installed 2 Pioneer subs in my car running in series from 1 bridged connection on a 2 channel amp, the problem I have is when I turn ON and OFF my stereo, I get a huge Kick from both the Subs, the came thing happens when I switch between inputs on my stereo, between CD and Tuner etc, I put my original Sub back in the car and the problem went away, out the new ones back in and the problem comes back, the kick that I get out of the Subs gets bigger the higher the Gain setting is on the AMP,
All the Wiring has been checked 3 times by 2 people and it is all hooked up as displayed on the following link
http://www.crutchfieldadvisor.com/learningcenter/car/subwoofers_wiring.html?subs=2&impedance=DVC4x2
Running at a 4 ohm load (Second Picture)
I took my car to the Local Car Audio shop and they stated that the setup I had should work fine, does anyone have any ideas, or has anyone seen this before
Please help?
Replies (4)
swez on 08/30/2006 10:00:42
That is a very strange observation.
Tell us more about your amp subs... make and model #'s. Same info on your HU too. (HU = Radio, CD player or music source unit)
Many older amps do not have anti-thump circuits in them. When we shut them off, turn them on or switch to other music sources, (CD to MP3 player or FM) some HU's will give a strong pulse to the amplifier or the amp reboots and thumps.
If it were me, the first thing I would do, is make sure your HU is properly grounded. Then, check the amp gains. They have to be matched to the HU source. (Ie: A 2.0 volt RCA output from HU, set amp gains at 2.0 volts) Are you using any bass boost off this amp or the HU?
As for changing subs and the problem goes away??? That's a hard one to figure out. If the old sub is low efficiency (very stiff cone) and your Pioneers are high efficiency, that would explain some of it.
It's probably there with your old sub, but not as noticable. If you watched the sub cone as someone works the controls, (Or use a Remote) chances are good that you'll see the old sub moving as you change sources, but it's not so noticable, audible)
More feedback please,
Swez
HERC on 08/30/2006 15:27:04
The spec of my amp is
http://www.theloudest.co.uk/?sectionid=2&page=view_product&product_id=74
The HU is http://www.pioneer.co.uk/uk/products/archive/DEH-P70BT/index.html
My old sub was a pioneer TS-W121SPL and the 2 new ones are Pioneer TS-W3004SPL, Not realy a big change. Both are DVC the only real divverence is there power handling
The HU is conected to the Cars wiring harnes by the standard Pioneer connector,
On a friends advice I have changed the Ground on the amp to a 1 gauge cable direct to the car chasie instead of the rear seat mounting bracket but that made no difference,
I have also noticed that when the AMP's gain settomgs are turned up over 1/4 the subs start to pulse (if this helps)
swez on 08/30/2006 19:36:03
Quote: "On a friends' advice I have changed the Ground on the amp to a 1 gauge cable direct to the car chassis instead of the rear seat mounting bracket but that made no difference."
Your friend had a good suggestion, but he needed to specify the grounding points for both HU and Amp need to be chassis grounds, to bare, burnished metal. (Clean, no rust, paint or surface tarnish present... we want shiney, bare metal) Once done, take a dolop of water repelling grease, oil or similar to prevent rust formation later.
A seat belt bolt or similar mounting hardware is usually a good option. However, your HU is now grounded to other components in the dash. (this is a bad plan for aftermarket HU's) I suggest re-grounding that specific wire (HU ground) to the floor pan. (Bare metal ect....) Why? Harness grounds off the dash are not always effective in high power amplification installs like this one. This problem is often called a "ground loop" noise problem. (Pops, engine whine, spark plug noise and such in the audio chain, are all common symtoms of a ground loop issue)
The amp gain control is the other aspect to consider here. Neither of the links noted in your reply, give details on the HU RCA output or amp's gain range.
Most HU's offer RCA outputs between 1.5 - 5.0 volts. Many of the newer models average at 2.0 volts. Most amps have an input adjustment of 1/4 - 4, 5 or even 6.0 volts. I cannot tell on this amp, what the range is. So, we have to use the S.W.A.G, (Scientific Wild-assed Guess) method. More on that later.
The amp specs say: Input sensitivity is...... <250 mV. What does that mean? I have no clue???
Contact the amp maker and ask for the "sensitivity range" of the gain control. "Please tell me the input gain sensitivity range settings for this amp". (I hope they say... "250mV - 4.0 volts" is the operational range of the gain control feature on this amp)
www.support@the loudest.co.uk
In the meantime, change your HU ground connection to the floor pan and see if that helps. The other side of this connumdrum, will be setting the amp gain control accurately. See what the Techs have to say at
"theloudest...."
Cheers Mate,
Swez
cplkittle on 08/31/2006 17:57:12
what is current ohm configuration and what was the old one? there could be a very audible difference if we are talking about a 8ohm to a 4ohm configuration. I have seen a 1ohm setup pop and not a 4ohm in the same situation (changing only the speakers). It's almost like if the resistance is lower than (x) the caps in the amp discharge through the speaker, if it is higher, they just bleed off gradually.
All the Wiring has been checked 3 times by 2 people and it is all hooked up as displayed on the following link
http://www.crutchfieldadvisor.com/learningcenter/car/subwoofers_wiring.html?subs=2&impedance=DVC4x2
Running at a 4 ohm load (Second Picture)
I took my car to the Local Car Audio shop and they stated that the setup I had should work fine, does anyone have any ideas, or has anyone seen this before
Please help?
Replies (4)
swez on 08/30/2006 10:00:42
That is a very strange observation.
Tell us more about your amp subs... make and model #'s. Same info on your HU too. (HU = Radio, CD player or music source unit)
Many older amps do not have anti-thump circuits in them. When we shut them off, turn them on or switch to other music sources, (CD to MP3 player or FM) some HU's will give a strong pulse to the amplifier or the amp reboots and thumps.
If it were me, the first thing I would do, is make sure your HU is properly grounded. Then, check the amp gains. They have to be matched to the HU source. (Ie: A 2.0 volt RCA output from HU, set amp gains at 2.0 volts) Are you using any bass boost off this amp or the HU?
As for changing subs and the problem goes away??? That's a hard one to figure out. If the old sub is low efficiency (very stiff cone) and your Pioneers are high efficiency, that would explain some of it.
It's probably there with your old sub, but not as noticable. If you watched the sub cone as someone works the controls, (Or use a Remote) chances are good that you'll see the old sub moving as you change sources, but it's not so noticable, audible)
More feedback please,
Swez
HERC on 08/30/2006 15:27:04
The spec of my amp is
http://www.theloudest.co.uk/?sectionid=2&page=view_product&product_id=74
The HU is http://www.pioneer.co.uk/uk/products/archive/DEH-P70BT/index.html
My old sub was a pioneer TS-W121SPL and the 2 new ones are Pioneer TS-W3004SPL, Not realy a big change. Both are DVC the only real divverence is there power handling
The HU is conected to the Cars wiring harnes by the standard Pioneer connector,
On a friends advice I have changed the Ground on the amp to a 1 gauge cable direct to the car chasie instead of the rear seat mounting bracket but that made no difference,
I have also noticed that when the AMP's gain settomgs are turned up over 1/4 the subs start to pulse (if this helps)
swez on 08/30/2006 19:36:03
Quote: "On a friends' advice I have changed the Ground on the amp to a 1 gauge cable direct to the car chassis instead of the rear seat mounting bracket but that made no difference."
Your friend had a good suggestion, but he needed to specify the grounding points for both HU and Amp need to be chassis grounds, to bare, burnished metal. (Clean, no rust, paint or surface tarnish present... we want shiney, bare metal) Once done, take a dolop of water repelling grease, oil or similar to prevent rust formation later.
A seat belt bolt or similar mounting hardware is usually a good option. However, your HU is now grounded to other components in the dash. (this is a bad plan for aftermarket HU's) I suggest re-grounding that specific wire (HU ground) to the floor pan. (Bare metal ect....) Why? Harness grounds off the dash are not always effective in high power amplification installs like this one. This problem is often called a "ground loop" noise problem. (Pops, engine whine, spark plug noise and such in the audio chain, are all common symtoms of a ground loop issue)
The amp gain control is the other aspect to consider here. Neither of the links noted in your reply, give details on the HU RCA output or amp's gain range.
Most HU's offer RCA outputs between 1.5 - 5.0 volts. Many of the newer models average at 2.0 volts. Most amps have an input adjustment of 1/4 - 4, 5 or even 6.0 volts. I cannot tell on this amp, what the range is. So, we have to use the S.W.A.G, (Scientific Wild-assed Guess) method. More on that later.
The amp specs say: Input sensitivity is...... <250 mV. What does that mean? I have no clue???
Contact the amp maker and ask for the "sensitivity range" of the gain control. "Please tell me the input gain sensitivity range settings for this amp". (I hope they say... "250mV - 4.0 volts" is the operational range of the gain control feature on this amp)
www.support@the loudest.co.uk
In the meantime, change your HU ground connection to the floor pan and see if that helps. The other side of this connumdrum, will be setting the amp gain control accurately. See what the Techs have to say at
"theloudest...."
Cheers Mate,
Swez
cplkittle on 08/31/2006 17:57:12
what is current ohm configuration and what was the old one? there could be a very audible difference if we are talking about a 8ohm to a 4ohm configuration. I have seen a 1ohm setup pop and not a 4ohm in the same situation (changing only the speakers). It's almost like if the resistance is lower than (x) the caps in the amp discharge through the speaker, if it is higher, they just bleed off gradually.
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